Trash compactor

ABSTRACT

A trash compactor comprising a flexible bellows-type, openended, trash-receiving chamber which is closed off by an end plug to form a variable volume chamber. The plug contains a highly efficient vacuum pump which reduces the pressure within the flexible chamber to a level substantially below atmospheric. This creates a pressure differential across the end walls of the flexible chamber which forces them toward one another to crush any trash within the chamber. In alternate form the variable chamber is defined by an open-ended, rigid trash-receiving cylinder having a plug displaceable toward the closed wall of the cylinder to compact the trash.

United States Patent [19] Powers TRASH COMPACTOR [76] Inventor: Richard T. Powers, 3623 Herschel Ave., Cincinnati, Ohio 45208 22 Filed: Aug. 20, 1973 21 1 Appl. No.: 389,576

[52] U.S. Cl 100/269 R; 100/52; 100/211;

100/295 [51] Int. Cl. B303 H23 [58] Field of Search 100/52, 53, 211, 269 R,

[ Aug. 19, 1975 3,835,769 Peterson 100/53 X ABSTRACT A trash compactor comprising a flexible bellows-type, open-ended, trash-receiving chamber which is closed off by an end plug to form a variable volume chamber. The plug contains a highly efficient vacuum pump which reduces the pressure within the flexible chamber to a level substantially below atmospheric. This References Cited creates a pressure differential across the end walls of UNITED STATES PATENTS the flexible chamber which forces them toward one 293,335 2/1884 Knapp 100 90 x another to crush any Within the chamber- In ]!372,190 3/1921 Randall et 1 oo 1 X ternate form the variable chamber is defined by an 1,703,783 2/1929 Schmidt 100/265 X open-ended, rigid trash-receiving cylinder having a 3,478,909 11/1969 Charles.... 100/295 UX lug displaceable toward the closed wall of the cylin- 3,575,103 4 1971 Charles.... 100 52 X der to compact the trash 3,736,863 6/1973 Brucker 100/53 X 3,835,767 9/1974 Peterson 100/53 5 Claims, 4 Drawing Figures x\\ \T\ 22 32 57 I I 1 5 6 54 36 J '4 23 2 38 3O 4O 50 52 PATENTED AUIH 9 I975 TRASH COMPACTOR The present invention relates to compaction devices and more specifically to trash compaction devices.

The recent emphasis for man to conserve his environment has prompted the development of devices that substantially reduce the volume of trash found in the ordinary home by compaction. This facilitates trash collection and makes more convenient to store trash in the household prior to collection.

Many different types of compactors have been developed and proposed. They all, however, use a plate or piston displaceable to reduce the volume in a trashreceiving chamber to compact the trash. This plate may be driven through mechanical gearing in the wellknown commercial types of trash compactors. Other devices either use water pressure, as shown in U.S. Pat. No. 3,654,855, or air pressure, as illustrated in US. Pat. No. 3,478,909 to force the plate to compact the trash.

All of these devices suffer from a common problem. While generally effective in the compaction of trash, they require a very rigid structure to accommodate the substantial compaction loads of up to 2,000 lbs. The structure forming the trash-receiving chamber must be able to resist this 2,000 lb. load in a longitudinal direction. As a result, most if not all of the devices proposed have been so heavy that it is necessary to make them stationary units, thus decreasing their versatility. Furthermore, the added structure greatly adds to the cost of the compaction unit and makes it economically unattractive for many individuals.

It is an object therefore of the present invention to provice a trash compaction unit that is highly simplified, effective and economical.

The above ends are achieved by a trash compaction unit comprising a means for forming a variable volume trash-receiving chamber. The chamber-forming means includes first and second opposed end walls relatively displaceable toward one another to reduce the volume of the chamber. A means is connected to the chamber for reducing its internal pressure below atmospheric to establish a pressure differential across the end faces to force them toward one another, thus compacting the trash in the chamber.

The above and other related objects and features of the present invention will be apparent from a reading of the following description of the disclosure shown in the accompanying drawing and the novelty thereof pointed out in the appended claims.

In the drawings:

FIG. 1 is a plan view of a trash compactor embodying the present invention;

FIG. 2 is a longitudinal section view of the trash compactor of FIG. 1 taken on line 22 of FIG. 1 in a trashreceiving condition;

FIG. 3 is a longitudinal section view of the trash compactor of FIG. 1 in a trash-compaction condition; and

FIG. 4 is a longitudinal section view of a trash compaction unit illustrating an alternate embodiment of the present invention.

FIGS. 1 and 2 show a trash compactor which comprises an integral flexible bellows basket, generally referred to at 10, having a bottom end wall 12 and an I open upper end defined by beveled lip 14. If the trash to be compacted is completely amorphous it is not necessary to stiffen end wall 12. However, if the trash inwalls 16 have sufficient internal stiffness to permit the bellows basket to stand freely in its expanded position shown in FIG. 2. An example of an elastomeric material suitable for this purpose is silicone rubber manufactured by Dow Chemical Company.

A disc-like plug 20 comprises circular upper and lower walls 21 and 23, respectively interconnected by a beveled side wall 22. This side wall seats in lip 14 to seal off the top of the bellows basket 10 and form a trash compaction chamber 24 of variable volume. The plug 20 has a handle 23 secured to side wall 22 which permits the plug 20 to be suitable stored on a hook when not in use. A pump with sufficient capacity to significantly lower the pressure in chamber 24, asdescribed later, is provided in plug 20. A type of pump fulfilling this requirement is a positive displacement pump, herein shown as a rotary vane pump 26. It should be apparent that other types of positive displacement pumps may also be used. The pump 26 has upper and lower circular plates 32 and 34 and an outer ring 36 defining an annular chamber in which a rotor 38 rotates about shaft and pulley assembly 40. As shown in FIG. 1, the axis of rotation of rotor 38 is eccentric relative to the center of the chamber in which the rotor 38 rotates. Rotor 38 has a series of radial slots 41 which receive vanes 42 urged outward against the ring 36 by springs 44. Thus, as the rotor 38 rotates the adjacent vanes define positive variable volume segments.

Lower wall 34 has a port 48 which connects the rotor chamber to an annular recess 28 in plug 20. Annular recess 28 connects with trash compaction chamber 24 through a perforated metal screen 30 of sufficient strength to resist local stresses of trash being compacted. Upper wall 32 has a port 46 which connects the rotor chamber to the atmosphere surrounding the trash compactor. If rotor 38 is rotated in a counterclockwise direction, as viewed in FIG. 1, air from within chamber 24 is exhausted through ports 48 and 46 to the atmosphere. If rotor 38 is rotated in a clockwise direction, air from the atmosphere enters port 48 and is transferred through port 46 into chamber 24.

Rotor 38 is driven through a belt 50, trained over pulley 40 and a drive pulley 52. Drive pulley 52 is driven by a suitable bidirectional electric motor 54 through a .bevel gear assembly referred to at 56. Motor 54 is controlled by the motor control system 58, schematically illustrated. While shown outside of plug 20, it would normally be contained inside. It comprises manually activated power switch which permits a source of electrical power to pass to motor 54 via a reversing switch 62 to drive rotor 38 counterclockwise. A cycle control device 64 activates the reversing switch 62 to change the direction of motion of the motor 54 to drive rotor 38 clockwise when trash in chamber 24 has been completed. The device 64 also actuates the cycle control power switch 60 to automatically terminate power to the motor 54 upon completion of a compaction cycle.

The cycle control device 64 may be a timing device which reverses the direction of motor 54 after a predetermined time period sufficient for trash to be compacted. The cycle control then may return the power switch 60 to the off position after a second predetermined time period sufficient for the unit to return to the beginning of a cycle. Alternately, the cycle control device may be pressure activated to reverse motor direction when a predetermined lowered pressure in chamber 24 is reached and to terminate power when the pressure again reaches atmospheric level.

To use the trash compactor the inside of bellows basket is lined with a suitable plastic trash bag 66. The side walls 16 of the bellows basket have sufficient internal rigidity to permit them to stand freely. As it is generated, compacted trash 68 is placed in bellows basket 10 to completely fill it in much the same way as one would fill a waste paper basket. When this is done the plug 20 is placed in the open end of the bellows basket 16 so that the beveled side wall 22 seats against the beveled lip 14. When the plug is in place the power switch 60 is turned on manually to connect a source of electrical power to the motor 54. This drives rotor 38 to exhaust air from the trash compaction chamber 24 via inlet port 48 and out of outlet port 46. If the vane pump 26 is between 80 and 90 percent efficient, it will reduce the pressure in trash compaction chamber 24 to a level of approximately 1%: psi. Since the pressure in the atmosphere is at 14.7 psi, there is approximately a 13 psi differential acting on the end walls 12 and the plug 20. This creates a substantial pressure force which forces them together with a total force equal to the area of the end wall times the pressure differential. For an end wall area of 14 inches in diameter a force of 2,000 lbs. is easily obtainable. This force is well within the compaction level attained by mechanical and pneumatic pressure trash compactors. This pressure force urges the end walls toward one another to compress the trash in chamber 24 and also to shorten the height of the side wall 16, as shown in FIG. 3. It can be seen in this figure that the convolutions of the bellows are greatly compressed. During this compression it is noted that the section modulus for these walls substantially increases, thereby resisting any inward deformation. This insures that the only movement is that of the bottom wall 12 toward the plug 20 to reduce the volume of chamber 24.

When the trash in chamber 24 is fully compacted the cylce control device 64 sends a signal to the reversing switch 62 to reverse the direction of the motor 54. This repressurizes trash compaction chamber 24 to an atmospheric level. The compacted trash then falls in compacted bundles to the bottom of the bellows basket 10. The plug 20 may be removed to permit further accumulation of uncompacted trash in bellows basket 10. The trash compaction cycle is repeated until bellows basket 10 is substantially full of compacted trash. The trash bag 66 may then be removed for suitable disposal.

Referring to FIG. 4 there is shown an alternate embodiment of the trash compactor. An open-ended cylinder has rigid side walls 70 and a bottom wall 72. A second wall 74 in the form of a circular disc is displaceable toward wall 72 to form a variable volume trashreceiving chamber 78. A rim 76 for wall 74 prevents it from rocking as it is displaced toward wall 72.

A positive displacement pump 80 (shown schematically) has a first port 82 connecting to chamber 78 and a second port 84 connected to the atmosphere. Pump 80 is driven by a bidirectional motor 86 in a first direction to discharge air from chamber 78 to lower its pressure beneath atmospheric. The pump 80, when driven in the opposite direction, discharges air into chamber 78 to bring its pressure level up to atmospheric. A motor control system similar to that shown in FIG. 1 may be employed to automatically achieve a trash compaction cycle.

When trash is to be compacted it is placed in chamber 78 and the wall 74 inserted. The pump 80 is driven in a direction to lower the pressure in chamber 78 below atmospheric and force walls 74 and 72 toward one another. This compacts the trash with force levels similar to those for the compactor of FIGS. 13. After the trash is compacted the pump 80 is reversed to bring the pressure back to an atmospheric level. The unit is then ready for another cycle.

Both of the trash compactors described above are highly effective in compacting trash. Since the material forming the compactor acts only as an interface between the air pressure and the trash it does not have to be structurally massive as in prior art compactors. This enables the unit to be provided as a portable unit easily carried from place to place. The simplicity of these units permits them to be manufactured at a cost level significantly lower than that for present day trash compactors.

Preferred embodiments of the present invention have been described. However, it should be apparent to those skilled in the art that it may be practiced in other forms without departing from its spirit and scope.

Having thus described the invention what is claimed as novel and desired to be secured by Letters Patent of the United Sates is:

l. A trash compactor comprising: means for forming a variable volume trash-receiving chamber, said chamber-forming means including first and second opposed end walls relatively displaceable toward one another to reduce the volume of said chamber, said chamber-forming means comprising: an open-ended cylindrical chamber having a bottom wall defining said first wall and a cylindrical side wall comprised of flexible material in a bellows form yieldable to reduce the axial height thereof, and a plug received in the open end of said cylindrical chamber thereby forming said second end wall; and

pressure-reducing means connected to said chamber for reducing the pressure therein below atmospheric to establish a pressure differential across said end walls to force them toward one another, thus compacting the trash in said chamber, said pressure-reducing means being carried by said plug.

2. A trash compactor as in claim 1 wherein said plug is disc-like and has a beveled edge received in a beveled lip at the open end of said cylindrical chamber so that atmospheric pressure urges said plug toward said flexible chamber.

3. A trash compactor as in claim 2 wherein said cylindrical side wall has inner and outer convolutions and further comprises a series of circular reinforcing rings in the inner convolutions of said bellows thereby a 6 strengthening the side wall against inward deformation 5. A trash compactor as in claim 1 wherein said presduring operation of said pressure-reducing means. sure-reducing means comprises a rotary vane pump 4. A trash compactor as in claim 2 wherein said first having a port connected to said interior of said chamend wall has means for reinforcing it thereby minimizber and a port connected to the atmosphere. ing build-up of stress concentration. 5 

1. A trash compactor comprising: means for forming a variable volume trash-receiving chamber, said chamber-forming means including first and second opposed end walls relatively displaceable toward one another to reduce the volume of said chamber, said chamber-forming means comprising: an open-ended cylindrical chamber having a bottom wall defining said first wall and a cylindrical side wall comprised of flexible material in a bellows form yieldable to reduce the axial height thereof, and a plug received in the open end of said cylindrical chamber thereby forming said second end wall; and pressure-reducing means connected to said chamber for reducing the pressure therein below atmospheric to establish a pressure differential across said end walls to force them toward one another, thus compacting the trash in said chamber, said pressure-reducing means being carried by said plug.
 2. A trash compactor as in claim 1 wherein said plug is disc-like and has a beveled edge received in a beveled lip at the open end of said cylindrical chamber so that atmospheric pressure urges said plug toward said flexible chamber.
 3. A trash compactor as in claim 2 wherein said cylindrical side wall has inner and outer convolutions and further comprises a series of circular reinforcing rings in the inner convolutions of said bellows thereby strengthening the side wall against inward deformation during operation of said pressure-reducing means.
 4. A trash compactor as in claim 2 wherein said first end wall has means for reinforcing it thereby minimizing build-up of stress concentration.
 5. A trash compactor as in claim 1 wherein said pressure-reducing means comprises a rotary vane pump having a port connected to said interior of said chamber and a port connected to the atmosphere. 